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Our Solar System Isn't Normal

npr.org

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Re: Our Solar System Isn't Normal

#61

Post by Retric »

teamonkey wrote: post #13
schiffern wrote: post #6

Earlier quoted context omitted.

Kepler uses occlusion, not wobbling.

Yes, and it's designed to detect Earth-sized planets as well as larger gas giants.

Can detect is one thing, can detect at the same distance is another. Assume you can detect an earth like planet at say 100 light years and a Jupiter sized planet at 1,000 light years and you find 1000x as many Jupiter sized planets that does not mean there are 1,000x as many just that you can detect them in 1,000x as much space.

Granted I don't know there search pattern but we are talking about less than 1,000 systems at this point. And I think we have found 2 reasonably earth like planets already which suggests there are at a minimum millions of them in this galaxy.

Re: Our Solar System Isn't Normal

#62

Post by chc »

qdog wrote: post #33

I think everyone here concentrating on sampling bias is missing the point. The evidence in solar systems so far does NOT fit the theory involving a frost line, and giants like Jupiter are unexpectedly observed tightly orbiting suns. Whether our solar system is normal is conjecture, but our model for how solar systems are(were?) formed is obviously flawed. Pretty interesting find, imho.

I don't see how the fact that gas planets are capable of migrating inward shows that our model for planetary formation is deeply flawed. I didn't think the current model said that it was impossible for planets to migrate inward.

The point about sampling bias is that our current techniques are bad at spotting systems like ours. If this is true (I think it is, but I'm not qualified to say), we wouldn't expect the evidence to fit our theory even if our theory were true because we are nearly incapable of finding evidence that does fit our theory no matter how much of it there is out there.

Re: Our Solar System Isn't Normal

#63

Post by chc »

asr wrote: post #54
banachtarski wrote: post #52

Earlier quoted context omitted.

This article definitely isn't communicating what you interpreted. Why are your comments about "most articles" relevant?

Agreed. For anyone else who routinely reads comments without reading the article, if this is still the top comment, I'd suggest you just go skim the article. (Aside: I'd guess it's because there are people like me, who often read comments before or without reading the article, that a well-written but not on-point comment like this can get upvoted. I wonder how you'd fix that?)

Well, the obvious answer would be: Track whether a user has clicked on the link and disable the vote buttons until they have.

Re: Our Solar System Isn't Normal

#64

Post by Alex3917 »

tocomment wrote: post #2

I would argue the exo-planets we have found so far are a very biased sample. We don't have great technologies for detecting solar systems like ours. And at least the first few years of planet hunting we'll tend to find a lot of large giants orbiting close to their stars since they're the easiest to find.

"I would argue the exo-planets we have found so far are a very biased sample."

All of science is based on sampling bias, by definition. That's one of the main reasons why science isn't a perfect lens for discovering truth. But just because something is probably wrong doesn't mean it isn't a 'scientific fact.'

Re: Our Solar System Isn't Normal

#66

Post by MartinCron »

johngalt wrote: post #23
unreal37 wrote: post #16

I had no idea that: "Or maybe it got ejected — astronomers are finding emigrant planets, lonely orbs that wander the universe with no star, just drifting. Maybe one of those used to live here." There are planets not orbiting stars? I searched Google for "emigrant planets" and the npr article is the number 1 result for that. I think he invented the term. What are these called if I wanted to find more information about…

They are more commonly called rouge planets. http://en.wikipedia.org/wiki/Rogue_planet

I always thought Mars was the rouge planet.

Re: Our Solar System Isn't Normal

#67

Post by username3 »

pekk wrote: post #40
kpierre wrote: post #32

Earlier quoted context omitted.

> But by no means is our solar system special in any light: it's only special in that its particular conditions produced lifeforms able to observe it. sorry, but i don't understand what's the logic here? it's not special, but it's only very special in sustaining/producing life? isn't that more than enough to call it special? :-)

Not in the requisite sense. Suppose that our existence depended on a purely random roll of a six-sided die coming up as 1. If the roll had come up anything else, we would not be here to reflect on it. But if it did come up as 1, that does not mean a mystical force guaranteed that it came up as 1. Our existence (whether likely or not) does not constitute evidence that our existence was guaranteed or predetermined. Low…

Suppose that our existence depended on a purely random roll of a six-sided die coming up as 1 on the first hundred rolls. It won't happen.

Re: Our Solar System Isn't Normal

#68

Post by mturmon »

lake99 wrote: post #29
mturmon wrote: post #15

Earlier quoted context omitted.

Yes, but they quoted both Steve Vogt and Mike Brown, who have devoted most of their careers to planet-finding. And both of them said that our solar system seems unusual. Since they are well aware of the biased sample issue, I would bet there is more to it than this. For instance, maybe they are able to model the effect of the bias, at least for some range of planetary masses, and the bias is not enough to explain the…

tocomment is right. Watch http://www.youtube.com/watch?v=8JTneTI82nE from 5:00 to 7:00. Yes, scientists may have been quoted in this article, but I have seen how most journalists mangle, ignore, or sensationalize things that were said.

That's a great video, and obviously she is very qualified to speak to this subject. I don't see how this shows that the GP comment is "right" in its assertion that this is just an effect of biased sampling.

I only had time to look at the first few minutes, but around 6:50 she does say that our solar system is "not that common", which she quantifies as "it could only be as much as 10-20% of star systems". Maybe that means So, this does not seem to contradict anything Vogt and Brown were quoted as saying.

Incidentally, I wasn't going by the statement in the NPR article, but also by the press release from UCSC (http://news.ucsc.edu/2012/12/tau-ceti.html), Vogt's home institution. I don't think that quote is subject to journalistic mangling.

Re: Our Solar System Isn't Normal

#69

Post by lake99 »

scott_s wrote: post #59
lake99 wrote: post #29

Earlier quoted context omitted.

tocomment is right. Watch http://www.youtube.com/watch?v=8JTneTI82nE from 5:00 to 7:00. Yes, scientists may have been quoted in this article, but I have seen how most journalists mangle, ignore, or sensationalize things that were said.

She also agrees with the main point of the original article, which is that our solar system is probably unusual. (From 6:47 to 7:00.)

Unusual is a subjective term. She says 10%-20% of the planetary systems are like ours. Are you saying that that was the point made in the original article too?

Re: Our Solar System Isn't Normal

#70

Post by scott_s »

lake99 wrote: post #69
scott_s wrote: post #59

Earlier quoted context omitted.

She also agrees with the main point of the original article, which is that our solar system is probably unusual. (From 6:47 to 7:00.)

Unusual is a subjective term. She says 10%-20% of the planetary systems are like ours. Are you saying that that was the point made in the original article too?

I don't know if it was, but I'm not concerned. What I took away from the original article was: We have a theory for how solar systems form. That theory assumes that our solar system is typical. The data we're finding does not agree with our theory, because the data indicates that our solar system is not typical.
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